Skip to main content

VISIBLE AND INVISIBLE STRABISMUS

By

DO YOU KNOW HOW MANY PEOPLE AROUND YOU HAVE STRABISMUS AN OF WHICH TYPE?

by Samidha Karmakar 5th May 2021


This blog is all about heterotopia and heterophoria differences. Binocular vision consists of three grades, the state of simultaneous vision with two seeing eyes occurs when the individual fixes his visual attention on an object to form a single mental impression at the same time.

Grades of binocular vision-

1. Simultaneous perception

2. Fusion

3. Stereopsis



In the above mention points are some way or the other are not followed neurological by our eye the errors will be seen. The anomalies could be a refractive error by birth or maturity, accommodation anomalies are deficient or decreased accommodation (presbyopia, insufficiency of accommodation, paralysis of accommodation), excessive and spasm of accommodation, ocular misalignment, innervations anomalies, palsies of EOM, Mechanical restriction, trauma, systemic disease.

 

 

As the blog is about visible squint and invisible squint it falls in ocular misalignment, as ocular misalignment is called strabismus (squint) it defines as when the individual is tenting to focus at an object, one eye is observed to align with the object axis whereas the other eye is on the other direction of the object axis. This could be due to suppression of one eye over the other in young which lead to lazy eye or in adults it is more of diplopia a newly grown squint, the reasons stated above could also be the reasons as anomalies.

What are the signs and symptoms.

  1. Diplopia

  2..Confusion

  3. Headache

  4. Asthenopia

  5. Eye pain

  6. Blurred vision

  7. Head posture

  8. C hin position (up or down)

  9. C losing or covering one eye in bright light

10.Lazy Eye (amblyopia)

11.Other ocular defects


 Apparent squint and pseudostrabismus sometimes misguide as squint, how?

 

  1. Children's with a broad and narrow nasal bridge ( Esotropia and exotropia )

  2. The lateral canthus is much narrow (pseudoexotropia)

  3. Orbital dystopia

  4. Anterior segment anomalies

  5. Marked facial asymmetry

  6. Enophthalmos and Exophthalmos 

  THE PHORIA (invisible squint)

Heterophoria is also known as "the physiological position of the rest" the phoria position is the position that the visual axes take with respect to one another in the absence of all stimuli to fusion. In simple words when the influence of fusion is interrupted the visual axis of the non fixing eye deviates. The fusion plays the important role in the case of finding the phorias, till the point the fusion is not removed temporarily the phoria will not be found.

 

  Classifications

 

  1. Esophoria

  2. Exophoria

  3. Right hyperphoria

  4. Left hyerphoria

  5. Incyclophoria

  6. Excyclophoria


THE TROPIA (visible squint )

 

Manifest deviation of the eyes from the ortho position cannot be overcome by the fusion reflex. 

Classifications

1. Concomitance deviation

  • Comitent strabismus – the angle of deviation is the same in all the 9 gazes (position) 
  • Incomitant strabismus – the angle of deviation is not the same in all 9 gazes (positions)

1. Directions of deviation

 

  • Esotropia
  • Exotropia
  • Right hypertropia
  • Left hypertropia
  • Incyclotropia
  • Excyclotropia 

  1. Constancy of deviation

  • Constant squint – deviation remains constant in all the time
  • Intermittent squint – deviation varies from time to time
  • Periodic squint – deviation varies with various distances
   1. Fixation Behavior
    Unilateral Squint

  • The same eye remain deviated all the time
  • Alternating squint – deviation keeps shifting between the two eyes
  • Bilateral squint – both the eyes deviate

   1. Time of onset

  • Congenital strabismus- present of deviation from birth
  • Acquired strabismus – deviation develops after 6 months.
    1. Etiology
  •      Paralytic strabismus- paralysis of any extraocular muscles
  • ·    Non-paralytic strabismus – accommodative or nonaccommodative heterotopia
  • ·    Primary heterotopia- convergence excess or insufficient and divergent excess or insufficiency

   1.    Secondary heterotopia – due to growing ocular diseases such as anisometropia, central chorioretinitis, etc.


   2.    Consecutive heterotopia – resulting from surgical overcorrection or spontaneous conversion of eso deviated eye into exo.


Comments

Post a Comment

Thank you

Popular posts from this blog

Eye Movement Dysfunction

By
The rotational movements of intorsion and extorsion are necessary to keep a viewed object stable and positioned on the appropriate part of the retina as the head is tilted from side to side. To illustrate imagine standing upright and looking at an arrow that is pointing superiorly.  Now tilt your head 45 degrees to the right, does the arrow move with your head? Now point at a 45 degree angle, hopefully not. Because of intorsion and extortion the arrow should still appear to be pointing superiorly. In this case the right eye has been intowarded and the left eye has been equivalently extorted so that the image falls on the same part of the retina as before the head tilt. Obviously our eye has a limited range of intorsion and extorsion. They cannot spin completely around within the orbit. And if we were to stand on our head the arrow would appear to change direction and appear to point inferiorly. Now, lets look at the movements produced by each of the extra oculum muscles. Medial and...
1 comment
Read more

Vision Therapy Exercise for Home

By
In this blog I am going to share vision therapy exercises which anyone can do easily at home. So let's get started.. Before performing this exercises you should have a comprehensive binocular vision exam to find any vision issues that you might have. It is also recommended to perform these exercises with a licensed optometrist about licensed therapists. Exercising your eyes is a lot like exercising your other muscles. Our eyes and our brain can be trained to get stronger performing eye exercises over a period of time. Focusing exercise which will train our eyes focusing ability to help us focus more efficiently for longer periods of time while reading a book or working on the computer. Equipments needed for the exercise: Any of the three objects will work: Detailed sticker on a stick. Pencil with small writing on it. Reading material with small print.   Eye patch. Distance glasses (If glasses are normally worn). Steps for Set Up: Wear an eye patch over one eye or close one eye...
2 comments
Read more

Unleashing Entrepreneurial Potential: Startup Opportunities for Optometrists in the Evolving World of Eye Care

By
Startup Opportunities for Optometrists Introduction: Optometry, a field focused on eye care and vision health, is ripe with entrepreneurial opportunities. Beyond traditional clinical practice, optometrists can harness their expertise and innovative mindset to create startups that bring about revolutionary changes in the industry. In this blog, we will delve into the exciting realm of startup opportunities for optometrists and explore how they can pave the way for transformative advancements in eye care. 1. Mobile Eye Care Clinics:  By establishing mobile eye care clinics, optometrists can reach underserved communities and remote areas with limited access to eye care services. Equipped with portable examination tools and vision screening equipment, these clinics can provide comprehensive eye exams, prescribe corrective eyewear, and detect common eye conditions. Such startups bring eye care directly to communities in need, promoting visual health and reducing barriers to access. 2. O...
2 comments
Read more